blk-mq: Use proper cpumask iterator

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queue_for_each_ctx() iterates over per_cpu variables under the assumption that
the possible cpu mask cannot have holes. That's wrong as all cpumasks can have
holes. In case there are holes the iteration ends up accessing uninitialized
memory and crashing as a result.

Replace the macro by a proper for_each_possible_cpu() loop and drop the unused
macro blk_ctx_sum() which references queue_for_each_ctx().

Reported-by: Xiong Zhou <jencce.kernel@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

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Thomas Gleixner 2016-03-19 11:30:33 +01:00 • committed by Jens Axboe

parent 5173cb814b

commit 897bb0c7f1

3 changed files with 6 additions and 17 deletions

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6

block/blk-mq-sysfs.c

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3

block/blk-mq.c

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14

include/linux/blk-mq.h

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